find the general solution for y''[x] = -y'[x]

the answer is y=c1e^(tx1) + c2e^(tx2) where c1, c2, x1, x2 are separate variables/constants...

i don't understand..i keep getting that y=ce^-x but that comes nowhere close to what the real answer is?

If anyone can help me, I would greatly appreciate it (ie worship them forever)

Thanks

ps. should this go in the diffeq forum? i wasn't sure because this is basic diffeq you learn in calc...